As of Version 7.0, VectorFieldPlot has been superseded by VectorPlot.
As of version 6.0, ButtonStyle has been superseded by the more general option BaseStyle.
Release
(Obsolete Mathematica Symbol) Since Version 2.0 (released in 1991), Release has been superseded by Evaluate and ReleaseHold.
Active
(Obsolete Mathematica Symbol) As of Version 6.0, Active has been superseded by Enabled.
As of Version 6.0, StylePrint has been superseded by Print[Style[expr, " style"]].
As of Version 6.0, NIntegrate natively supports InterpolatingFunction objects.
As of Version 7.0, DesignedRegress has been superseded by LinearModelFit.
As of Version 7.0, DesignMatrix is part of the built-in Mathematica kernel.
The built-in function Fit finds a least-squares fit to a list of data as a linear combination of the specified basis functions. The functions Regress and DesignedRegress ...
The built-in function FindFit allows you to perform nonlinear least squares fitting. The function NonlinearRegress gives a number of regression diagnostics and allows you to ...